var aneObj = function () {
    //start point control point end point(sin)
    this.rootx = [];
    this.headx=[];
    this.heady=[];
    this.alpha=0;
    this.amp=[];

}
aneObj.prototype.num = 50;
aneObj.prototype.init = function () {
   
    for (var i = 0; i < this.num; i++) {
        this.rootx[i] = i * 16 + Math.random() * 20;
        this.headx[i]=this.rootx[i];
        this.heady[i]=canHeight-250+Math.random()*50;
        this.amp[i]=Math.random()*50+50;

    }
}
aneObj.prototype.draw = function () {
    this.alpha+=deltaTime*0.0008;
    var l=Math.sin(this.alpha);//[-1,1]
    ctx2.save();
    ctx2.lineWidth = 20;
    ctx2.strokeStyle = '#3b154e';
    ctx2.lineCap = 'round';
    ctx2.globalAlpha=0.6;
    for (var i = 0; i < this.num; i++) {
        ctx2.beginPath();
        ctx2.moveTo(this.rootx[i], canHeight);
        this.headx[i]=this.rootx[i]+l*this.amp[i];
        ctx2.quadraticCurveTo(this.rootx[i], canHeight - 100,this.headx[i],this.heady[i]);
        ctx2.stroke();
    }
    ctx2.restore();
}